Develop Reference

making unique strings after getting value from hashset?

Okay So I have this Hashset that contains 3 items and I want to apply some logic on it such that I am able to append some predefined 3 values for the each item present inside the hashset
for example,
HashSet<string> hs = new HashSet<string>(); //it could be string or some other class object
hs.add("Red");
hs.add("Yellow");
hs.add("Blue");
//Some predefined values for those strings that I want to append to them
string[] str = {Alpha, Beta, Gamma}
The output I desire is:
unique strings associating "RedAlpha", "YellowBeta", "bluegamma"
for example s1 = "RedAlpha", s2 = "YellowBeta", s3 = "bluegamma";
I then want to apply some different logic to each of them later but then I guess that is a different thing
My Tried code
int count = 1;
int index = 0;
string s = "";
foreach(string strr in hs)
{
string s + count = strr + str[index]; // I don't know how to make new unique string
count++;
index++;
}
My other Tried Code,
foreach(string strr in hs)
{
string s = strr + str[index];
s = s + ","
index++;
}
s.split(",");

When you want to merge 2 collection together and perform some operation on them, use the Zip method. See this answer for an explanation of Zip method.
Here is how to achieve what you need:
HashSet<string> hs = new HashSet<string>();
hs.Add("Red");
hs.Add("Yellow");
hs.Add("Blue");
string[] str = { "Alpha", "Beta", "Gamma" };
List<KeyValuePair<string, string>> kvps =
hs.Zip(str, (left, right) => new KeyValuePair<string, string>(left, right))
.ToList();
If you want a dictionary, it is straight forward as well:
Dictionary<string, string> kvps =
hs.Zip(str, (left, right) => new { left, right })
.ToDictionary(x => x.left, x.right);

Put them in a list:
int index = 0;
var list = new List<string>();
foreach(string strr in hs)
{
list.Add(strr + str[index]);
index++;
}
Console.WriteLine(list[0]); //RedAlpha

split string array c#

So I have multiple arrays of strings. Within each array I have a string which uses '|' as a separator. What I need is to create a string with the first elements of the array up until the '|'.
So in the example I need 6485,6486,6487,6509,6510,6511,6533,6534,6535,|

Use String.Split() to split the original strings, then store the first ones in a separate array, then use String.Join() to concatenate them
string[] tempStrings = new string[stringArray.Length];
for(int i = 0; i < stringArray.Length; i++)
{
tempStrings[i] = stringArray[i].Split(#"|")[0];
}
string result = String.Join(",", tempStrings);

Using System.Linq :
string[] temp = new string[] { "1,2,3|4,5,6|7,8,9", "10,11,12|13,14,15", "16,17,18"};
var result = String.Join(",", temp.Select(x => x.Split('|').FirstOrDefault())
.ToList());
With null and empty values :
string[] temp = new string[] { "1,2,3|4,5,6|7,8,9", "10,11,12|13,14,15", "16,17,18", "", null };
var result = String.Join(",", temp.Select(x => x?.Split('|').FirstOrDefault())
.Where(x => !string.IsNullOrWhiteSpace(x))
.ToList());

C# 2 string arrays to List<string, string>

Assuming the 2 string arrays are the same length and not empty how can I make a List of the contents?
I had a Dictionary working, but now I need to be able to use duplicate keys so I am resorting to a List.
string[] files = svd.file.Split(",".ToCharArray());
string[] references = svd.references.Split(",".ToCharArray());
Dictionary<string, string> frDictionary = new Dictionary<string, string>();
frDictionary = files.Zip(rReferences, (s, i) => new { s, i })
.ToDictionary(item => item.s, item => item.i);
I could do it like:
List<string, string> jcList = new List<string, string>();
and then just have a double loop into the two arrays but I know a faster way must exist.

ILookup<string,string> myLookup =
files.Zip(rReferences, (s, i) => new { s, i })
.ToLookup(item => item.s, item => item.i);
will create a Dictionary-like structure that allows multiple values per key.
So
IEnumerable<string> foo = myLookup["somestring"];

A List containing elements with two strings each is simplest implemented with a
List<T>
and
T == Tuple<string,string>
Then use a loop to build your list from the two arrays:
string[] s1 =
{
"1", "2"
};
string[] s2 =
{
"a", "b"
};
var jcList = new List<Tuple<string,string>>();
for (int i = 0; i < s1.Length; i++)
{
jcList.Add(Tuple.Create(s1[i], s2[i]));
}
or using LINQ:
var jcList = s1.Select((t, i) => Tuple.Create(t, s2[i])).ToList();

Sorting a string based on prefixes

If you are given an array with random prefixes, like this:
DOG_BOB
CAT_ROB
DOG_DANNY
MOUSE_MICKEY
DOG_STEVE
HORSE_NEIGH
CAT_RUDE
HORSE_BOO
MOUSE_STUPID
How would i go about sorting this so that i have 4 different arrays/lists of strings?
So the end result would give me 4 string ARRAYS or lists with
DOG_BOB,DOG_DANNY,DOG_STEVE <-- Array 1
HORSE_NEIGH, HORSE_BOO <-- Array 2
MOUSE_MICKEY, MOUSE_STUPID <-- Array 3
CAT_RUDE, CAT_ROB <-- Array 4
sorry about the names i just made them up lol
var fieldNames = typeof(animals).GetFields()
.Select(field => field.Name)
.ToList();
List<string> cats = new List<string>();
List<string> dogs = new List<string>();
List<string> mice= new List<string>();
List<string> horse = new List<string>();
foreach (var n in fieldNames)
{
var fieldValues = typeof(animals).GetField(n).GetValue(n);"
//Here's what i'm trying to do, with if statements
if (n.ToString().ToLower().Contains("horse"))
{
}
}
So i need them to be splitted into STRING ARRAYS/STRING LISTS and NOT just strings

string[] strings = new string[] {
"DOG_BOB",
"CAT_ROB",
"DOG_DANNY",
"MOUSE_MICKEY",
"DOG_STEVE",
"HORSE_NEIGH",
"CAT_RUDE",
"HORSE_BOO",
"MOUSE_STUPID"};
string[] results = strings.GroupBy(s => s.Split('_')[0])
.Select(g => String.Join(",",g))
.ToArray();
Or maybe something like this
List<List<string>> res = strings.ToLookup(s => s.Split('_')[0], s => s)
.Select(g => g.ToList())
.ToList();

var groups = fieldNames.GroupBy(n => n.Split('_')[0]);
Usage
foreach(var group in groups)
{
// group.Key (DOG, HORSE, CAT, etc)
foreach(var name in group)
// all names groped by prefix
}

foreach (String s in strings)
{
if (s.StartsWith("CAT_")
cats.Add(s);
else if (s.StartsWith("HORSE_")
horses.Add(s);
// ...
}
Or:
foreach (String s in strings)
{
String[] split = s.Split(new Char [] { '_' });
if (split[0].Equals("CAT")
cats.Add(s);
else if (split[0].Equals("HORSE")
horses.Add(s);
// ...
}
But I would prefer the first one.

Algorithmically, I'd do the following:
Parse out all unique prefixes by using the "_" as your delimeter.
Loop through your list of prefixes.
2a. Retrieve any values that have your prefix (loop/find/regex/depends on structure)
2b. Place retrieved values in a List.
2c. Sort list.
Output your results, or do what you need with your collections.

You can order the list up front and sort by prefix:
string[] input = new string[] {"DOG_BOB","CAT_ROB","DOG_DANNY","MOUSE_MICKEY","DOG_STEVE","HORSE_NEIGH","CAT_RUDE","HORSE_BOO","MOUSE_STUPID"};
string[] sortedInput = input.OrderBy(x => x).ToArray();
var distinctSortedPrefixes = sortedInput.Select(item => item.Split('_')[0]).Distinct().ToArray();
Dictionary<string, string[]> orderedByPrefix = new Dictionary<string, string[]>();
for (int prefixIndex = 0; prefixIndex < distinctSortedPrefixes.Length; prefixIndex++)
{
string prefix = distinctSortedPrefixes[prefixIndex];
var group = input.Where(item => item.StartsWith(prefix)).ToArray();
orderedByPrefix.Add(prefix, group);
}

With LINQ, using something like
names.GroupBy(s => s.Substring(0, s.IndexOf("_"))) // group by prefix
.Select(g => string.Join(",", g)) // join each group with commas
.ToList(); // take the results
See it in action (some extra .ToArray() calls included for .NET 3.0 compatibility)

This LINQ expression does what you want.
var result = data.GroupBy(data.Split('_')[0])
.Select(group => String.Join(", ", group))
.ToList();
For a list of lists of strings use this expression.
var result = data.GroupBy(data.Split('_')[0])
.Select(group => group.ToList())
.ToList();

How to find the number of each elements in the row and store the mean of each row in another array using C#?

I am using the below code to read data from a text file row by row. I would like to assign each row into an array. I must be able to find the number or rows/arrays and the number of elements on each one of them.
I would also like to do some manipulations on some or all rows and return their values.
I get the number of rows, but is there a way to to loop something like:
*for ( i=1 to number of rows)
do
mean[i]<-row[i]
done
return mean*
var data = System.IO.File.ReadAllText("Data.txt");
var arrays = new List<float[]>();
var lines = data.Split(new[] {'\r', '\n'}, StringSplitOptions.RemoveEmptyEntries);
foreach (var line in lines)
{
var lineArray = new List<float>();
foreach (var s in line.Split(new[] {','}, StringSplitOptions.RemoveEmptyEntries))
{
lineArray.Add(Convert.ToSingle(s));
}
arrays.Add(lineArray.ToArray());
}
var numberOfRows = lines.Count();
var numberOfValues = arrays.Sum(s => s.Length);

var arrays = new List<float[]>();
//....your filling the arrays
var averages = arrays.Select(floats => floats.Average()).ToArray(); //float[]
var counts = arrays.Select(floats => floats.Count()).ToArray(); //int[]

Not sure I understood the question. Do you mean something like
foreach (string line in File.ReadAllLines("fileName.txt")
{
...
}

Is it ok for you to use Linq? You might need to add using System.Linq; at the top.
float floatTester = 0;
List<float[]> result = File.ReadLines(#"Data.txt")
.Where(l => !string.IsNullOrWhiteSpace(l))
.Select(l => new {Line = l, Fields = l.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries) })
.Select(x => x.Fields
.Where(f => Single.TryParse(f, out floatTester))
.Select(f => floatTester).ToArray())
.ToList();
// now get your totals
int numberOfLinesWithData = result.Count;
int numberOfAllFloats = result.Sum(fa => fa.Length);
Explanation:
File.ReadLines reads the lines of a file (not all at once but straming)
Where returns only elements for which the given predicate is true(f.e. the line must contain more than empty text)
new { creates an anonymous type with the given properties(f.e. the fields separated by comma)
Then i try to parse each field to float
All that can be parsed will be added to an float[] with ToArray()
All together will be added to a List<float[]> with ToList()

Found an efficient way to do this. Thanks for your input everybody!
private void ReadFile()
{
var lines = File.ReadLines("Data.csv");
var numbers = new List<List<double>>();
var separators = new[] { ',', ' ' };
/*System.Threading.Tasks.*/
Parallel.ForEach(lines, line =>
{
var list = new List<double>();
foreach (var s in line.Split(separators, StringSplitOptions.RemoveEmptyEntries))
{
double i;
if (double.TryParse(s, out i))
{
list.Add(i);
}
}
lock (numbers)
{
numbers.Add(list);
}
});
var rowTotal = new double[numbers.Count];
var rowMean = new double[numbers.Count];
var totalInRow = new int[numbers.Count()];
for (var row = 0; row < numbers.Count; row++)
{
var values = numbers[row].ToArray();
rowTotal[row] = values.Sum();
rowMean[row] = rowTotal[row] / values.Length;
totalInRow[row] += values.Length;
}